1. Field of the Invention
The present invention generally relates to a tire monitoring device, and more particularly relates to a tire monitoring device for monitoring the conditions of tires, which is provided with a simplified code learning process.
2. Description of the Related Art
Many related technologies and devices for confirming the position relationship between the tire pressure monitor and the tires have been proposed in the conventional arts. For example, Taiwan Patent Application No. 089117036 entitled “Method for Monitoring Tire Pressure of Pneumatic Tire and Device Therefor” filed on Aug. 22, 2000 and commonly assigned to the assignee of the present application, discloses a device which comprises sensor modules installed in each of the pneumatic tires for sensing the conditions of the tires, and then encoding and transmitting the conditions of the tires by radio frequency signals. The device also has a decoder module comprising a radio frequency antenna module for receiving the radio frequency signals transmitted by the sensor module, a memory for recording the value of the predetermined range of the tire conditions and the monitoring data of the tire conditions, a processor for decoding the received radio signals and comparing the decoded signals with the predetermined value in the memory so as to determine the present conditions of the pneumatic tires, a display device for displaying the present conditions of the pneumatic tires, and a buzzer. Such device is used for detecting the abnormal pressure and temperature conditions of the tire and identifying each tire to confirming which tire is in the abnormal conditions.
However, in the prior art, while the decoder module identifies the relationship between the code of the sensor module and the positions of the pneumatic tires, the operator has to deflate the tires of the vehicle. By rapid changing of the tire pressure, the sensor modules installed in the tires continuously transmit signals which can be decoded by the decoder, thereby identifying the relationship between the position of the tires and the sensor modules installed therein. Then, the deflated tires of the vehicle have to be inflated before the driver use the vehicle again. Obviously, such process is relatively time consuming, inconvenient, and complicated.
Taiwan Patent Application No. 090112305 entitled “Code Learning Device of Tire Pressure Monitor”, filed on May 17, 2001 and commonly assigned to the assignee of the present application, discloses a code learning device and a hand kit code learning device of tire pressure monitor. However, the foregoing code learning devices require additional device and operation so as to complete the code learning process. This code learning process is complex and complicated and the driver does not often have to replace tires, so the driver may forget how to operate the code learning device when the driver has to proceed with the code learning process.
Further, U.S. Pat. No. 6,259,361 issued to Robillard et al. on Jul. 10, 2001 entitled “Tire Monitoring System”, discloses a tire pressure monitoring system using the difference of the temperature and the accelerometer to discriminate between front tires and rear tires, and identify the locations of the tires. However, the front tires typically have a higher temperature than the rear tires because the front tires are the driving tires and close to the engine of the vehicle, but the difference of the temperatures between the front tires and the rear tires are usually affected by external temperature so as to cause incorrect results.
Therefore, the foregoing conventional code learning methods are unable to provide a fast and effective code learning mode for the tire pressure monitor installed in the motor vehicle to define the identifying code of each pneumatic tire. There exists a need for a code learning device of tire pressure monitor to simplifying the code learning process of the tire pressure monitor.